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Updated: Aug 6, 2026
A Simple Composite Phenotype Scoring System for Evaluating Mouse Models of Cerebellar Ataxia
Published on: May 21, 2010
Cerebellar cognitive affective syndrome (CCAS) and [18F]-FDG PET findings in spinocerebellar ataxia type SCA27B
Laurine Cros1, David Pellerin2, Thomas Palpacuer3
1Service de Neurologie, Centre Hospitalier Régional Universitaire de Nancy, Hôpital Central, Nancy, France.
Background:
Spinocerebellar ataxia type 27B (SCA27B) is caused by ≥ 250 GAA repeat expansions in intron 1 of the FGF14 gene. While motor symptoms are well documented, cognitive manifestations remain insufficiently explored. The cerebellar cognitive affective syndrome scale (CCAS scale) provides a framework for assessing cognition.
Methods:
We conducted a prospective study at Nancy University Hospital. The primary objective was to determine the prevalence of cerebellar cognitive affective syndrome. We subsequently characterized the cognitive profile using a standardized neuropsychological battery, evaluated quality of life, and examined the associations between CCAS score, GAA repeat length, motor severity, and age at onset. A [18F]-FDG PET metabolic analysis was performed, including individual visual analysis, followed by a whole-brain voxel-by-voxel comparison between SCA27B patients, healthy controls, and MSA patients.
Results:
Seventeen patients with genetically confirmed SCA27B were included. Motor symptoms were moderate (mean SARA score: 7 ± 6.2/40). Definite cerebellar cognitive affective syndrome (≥ 3 failed subtests) was identified in 41% (7/17) of the patients. The comprehensive neuropsychological evaluation revealed mild-to-moderate cognitive impairment; across all cognitive functions tested, fewer than 12% of patients showed cognitive impairment, except for social cognition (23.6%). The PET scan showed preserved cerebellar metabolism in individual analyses (2 patients with hypometabolism). Whole-brain voxel-based analysis, when compared to healthy controls, identified 5 clusters of hypometabolism, with no hypermetabolism.
Conclusion:
This study is among the first to investigate cognitive impairment in patients with SCA27B using the CCAS scale and comprehensive neuropsychological testing. A substantial prevalence of cerebellar cognitive affective syndrome was observed, even if the decrease of cerebellar metabolic was modest. These findings highlight the need for systematic screening of cognitive and nonmotor symptoms to improve multidisciplinary management.
